Assembly for the Treatment of Bifurcations

ABSTRACT

A stent for the endoluminal treatment of stenosis at a vessel bifurcation comprises at least two cylindrical portions extending along different axes. A catheter and a mandrel for placing the stent are described as well.

The present invention relates to an assembly intended for endoluminaltreatment of those blood vessel bifurcations affected by stenosis.

Particularly, the invention relates to an assembly intended for theendoluminal treatment of bifurcations with stenosis limited to onebranch, typically the side branch.

Stents are known to be used for the endoluminal treatment of bloodvessels affected by stenosis. The vessel inner diameter, which ispathologically narrowed by the presence of stenosis, is dilated bycarrying out an angioplasty operation by means of a catheter. By usingthe stent, the vessel wall can be supported and kept dilated such as toprevent the inner diameter from narrowing back after the angioplastyoperation.

In the particular field of bifurcation treatment, the traditional stentsof cylindrical shape suffer from the drawback that they do not provide asuitable support to all bifurcation areas.

By defining a main branch and a side branch within the bifurcation, ifthe stenosis is located only within the side branch, placing a stentwithin the main branch is not required. In this case, the most proximalarea of the side branch (see for example the area indicated with A inthe annexed FIG. 1 a) is devoided of any support, since the traditionalstent being placed in the side branch will not cover it.

Similarly, the so-called carina, i.e. the bifurcation area (see forexample the area indicated with B in the annexed FIG. 1 b), may lacksuitable support since the accuracy in placing the stent is only ensuredby the operator's skill. Neither the traditional stents, nor thecatheter employed for placing them offer the possibility of checking thelocation relative to the carina. Therefore, the case may occur that,wishing to prevent the stent from interfering in the blood stream of themain branch after it has been positioned (such as in the example in FIG.1 c), the operator will tend to place it slightly deeper within the sidebranch.

The object of the present invention is to conceive and provide acatheter and a stent allowing to overcome the drawbacks mentioned abovewith reference to the prior art.

Particularly, the task of the present invention is to provide a stentcapable of providing a suitable support both to the part most proximalof the lateral side and the bifurcation carina. Furthermore, the task ofthe present invention is to provide a catheter assembly allowing toaccurately check the location of the stent upon implantation.

This object and this task are achieved by means of a stent, cathetersand a catheter assembly, respectively, in accordance with claims 1, 10,22 and 30.

Further characteristics and advantages of the invention will appear fromthe description given below of preferred embodiments, which are intendedto be indicative and non-limiting examples, with reference to theannexed figures, in which:

FIGS. 1 a, 1 b and 1 c schematically illustrate the placement of a stentaccording to the prior art in a bifurcation affected by stenosis in theside branch, in dotted line;

FIG. 2 schematically illustrate a first embodiment of a first catheteraccording to the invention;

FIG. 2 a schematically illustrates a section taken along the line IIafrom FIG. 2;

FIG. 2 b schematically illustrates a second embodiment of a firstcatheter according to the invention;

FIG. 2 c illustrates a detail of the catheter from FIG. 2 b;

FIG. 3 schematically illustrates an embodiment of a second catheteraccording to the invention;

FIG. 4 schematically illustrates an assembly comprising the cathetersfrom FIGS. 2 and 3 according to the invention;

FIG. 5 schematically illustrates a first embodiment of a stent accordingto the invention;

FIG. 5 a illustrates a section taken along the line Va from FIG. 5;

FIG. 6 illustrates an assembly according to the invention comprising thecatheters from FIG. 2 and the stent from FIG. 5;

FIG. 7 illustrates an assembly according to the invention comprising thecatheters from FIGS. 2 and 3 and the stent from FIG. 5;

FIG. 8 illustrates the assembly from FIG. 7 in a first step of usewithin a bifurcation;

FIG. 9 illustrates the assembly from FIG. 7 in a second step of usewithin a bifurcation;

FIG. 10 illustrates the stent from FIG. 5 when placed in a bifurcation;

FIG. 11 illustrates a second embodiment of a stent according to theinvention;

FIG. 11 a illustrates a section taken along the line XIa from FIG. 11;

FIG. 12 illustrates the stent from FIG. 11 when placed in a bifurcation;

FIG. 13 illustrates a third embodiment of a stent according to theinvention;

FIG. 13 a illustrates a section taken along the line XIIIa from FIG. 13;

FIG. 14 illustrates the stent from FIG. 13 when placed in a bifurcation;

FIG. 15 illustrates the stent from FIG. 5 when placed in a bifurcationtogether with a stent of the known type.

With reference to the above figures, with 100 has been indicated a firstcatheter as a whole. The first catheter 100 comprises a tubular body110, known per se, having a proximal end 115 and a distal end 120, knownper se. The distal end 120, in turn, comprises a balloon 130 forangioplasty and a distal port for a guide wire 140, as is known in theart.

The first catheter 100 further comprises an eyelet 150 being arrangedlaterally to the tubular body 110, and integral therewith.

In accordance with a preferred embodiment of the first, catheter 100according to the invention, the eyelet 150 defines an x-x axis which islocally parallel to the tubular body 110 of catheter.

In accordance with an embodiment, the eyelet comprises a substantiallyunextensible thread slot.

In accordance with a preferred embodiment, the eyelet 150 comprises atube length being structurally fastened to the tubular body 110 such asto be integral therewith.

The structural fastening between the tubular body 110 and the eyelet 150can comprise for example a gluing or welding 160 such as in the examplefrom FIG. 2 a. The structural fastening can also comprise a sheath 170simultaneously enveloping the tubular body 110 and the eyelet 150, suchas shown in the example from FIG. 2 c. Alternatively, the eyelet 150 andthe tubular body placed beside it can be made as one piece by extrusion.Finally, the structural fastening between the tubular body 110 and theeyelet 150 can also comprise any other element which is deemed suitableto ensure a firm fastening of the catheter in any usage condition.

The length of the tube comprised within the eyelet 150 for example canbe cut along a perpendicular plane relative to x-x axis, such as in theexample from FIG. 2. The length of tube can also be cut along a curvedand biased surface relative to the x-x axis, such as in the example fromFIG. 2 c.

The eyelet 150 is placed at a preset distance from the distal end 120and particularly the balloon 130.

The first catheter 100 comprises a proximal port for the guide wire,which is known per se. In accordance with a preferred embodiment, thisproximal port 180 is placed proximal of the eyelet 150.

With 200 has been indicated a second catheter according to the inventionas a whole. The second catheter 200 comprises a tubular body 210 knownper se having a proximal end and a distal end 220, which are known perse. The distal end 220 comprises in turn an angioplasty balloon 230 anda distal port for a guide wire 240, as is known in the art.

The second catheter 200 further comprises a shoulder 250 being arrangedon the tubular body 210. The shoulder 250 comprises an abrupt variationin the outer diameter of tubular body 210. The variation is arrangedsuch that the immediately distal diameter relative to the shoulder 250is smaller than the outer diameter such as defined by the shoulderitself.

The shoulder 250 can comprise a step perpendicular to the outer surfaceof tubular body 210 as in the example from FIG. 3, or rather maycomprise a tapering joining the shoulder maximum diameter to the tubularbody diameter, such as in the example in FIG. 4.

With reference to FIGS. 5 to 10, with 310 is indicated a firstembodiment of a stent according to the invention as a whole.

The stent 310 comprises a first cylindrical portion 311 and a secondcylindrical portion 312. The cross-section of the cylindrical portions311 and 312, in accordance with the geometric definition of cylinder inthe broadest meaning of the word, either elliptic or any other closedloop which may be suitable for the particular use of a stent 310.

The first portion 311 and the second portion 312 are structurallyconnected to each other by means of at least two bridges 313. Thebridges 313 engage a first length, along the closed loops being definedby the cross section of the stent. For example, the first length of theclosed loop being defined by the first portion 311, engaged by thebridges 313, is indicated with P in FIG. 5 a. A second length of theclosed loop is thus also defined, which is complementary to the firstone and is not interested by the presence of the bridges 313. Thissecond length is indicated with S in FIG. 5 a.

In the stent 310 according to the invention, the first length P isshorter than second length S. In other words, the structural connectionbetween both portions 311 and 312 of the stent 310 comprises a pluralityof bridges 313 being unevenly distributed over the closed loop beingdefined by the cross-section of the portions.

In accordance with an embodiment, the first length P is shorter than thehalf, preferably one third and still more preferably shorter than onefourth of the length of second length S.

The y-y axis of the first portion 311 and the z-z axis of the secondportion 312 are distinct. Furthermore, the closed loop defined by thecross-section of the first portion 311 is at last partially comprised inthe closed loop being defined by the cross-section of the second portion312. In other words, the proximal end of the first portion 311 isconnected to the distal end of the second portion 312 by bridges 313.

In accordance with an embodiment, the bridges 313 have different lengthsand/or elasticity from one another. The bridges being closer to thefirst length P of the closet loop are required to have a smaller lengthand/or elasticity than the bridges arranged proximal of the ends of thefirst length P.

In accordance with one embodiment of the stent, those bridges beingclosest to the center of the first length P are rectilinear, whereas thebridges arranged proximal of the ends of the first length P comprisebends. This configuration allows to obtain more yielding bridges, as iswell known in the stent field.

In accordance with another embodiment, the bridges are made of differentmaterials. Particularly, those bridges being closest to the center offirst length P are made of a harder material, whereas those bridgesbeing arranged proximal of the ends of the first length P are made of amore elastic material.

With reference to FIGS. 11, 11 a and 12, with 320 there is indicated asecond embodiment of a stent according to the invention as a whole.

The stent 320 comprises a first cylindrical portion 321 and a secondcylindrical portion 322. The cross-section of the cylindrical portions321 and 322, in accordance with the geometric definition of cylinder inthe broadest meaning of the word, can be circular, elliptical or anyother loop which may be suitable to the particular use of the stent 320.

The first portion 321 and the second portion 322 are structurallyconnected to each other by means of at least two bridges 323. Thebridges 323 engage a first length along the closed loops being definedby the cross section of the stent. For example, the first length of theclosed loop defined by the first portion 321, which is engaged by thebridges 323, is indicated with P in FIG. 11 a. A second length of theclosed loop is thus also defined, which is a complementary length to thefirst one and is not interested by the presence of the bridges 323. Thissecond length is indicated with S in FIG. 11 a.

In the stent 320 according to the invention, the first length P isshorter than second length S. In other words, the structural connectionbetween both portions 321 and 322 of the stent 320 comprises a pluralityof bridges 323 unevenly distributed over the closed loop being definedby the cross section of the portions.

In accordance with one embodiment, the first length P is shorter thanhalf, preferably shorter than one third, and still more preferably onefourth of second length S.

The y-y axis of the first portion 321 and the z-z axis of the secondportion 322 are different. Furthermore, the closed loops being definedby the cross sections of the first portions 311 and second portions 312are disjoint and have only a part of the perimeter in common. In otherwords, the proximal end of first portion 321 is connected by means ofthe bridges 323 to the proximal end of second portion 322.

In accordance with an embodiment, the bridges 323 have different lengthsand/or elasticities. Those bridges being closest to the center of firstlength P of the closed loop are required be shorter and/or less elasticthan the bridges arranged proximal of the ends of the first length P.

With reference to FIGS. 13, 13 a and 14, with 330 is indicated a thirdembodiment of a stent according to the invention as a whole.

The stent 330 comprises both the characteristics of the first 310 andsecond 320 embodiments of the stent according to the invention.

The stent 330 comprises a first cylindrical portion 331, a secondcylindrical portion 332 and a third cylindrical portion 334. The crosssection of the cylindrical portions 331, 332 and 334, in accordance withthe geometric definition of cylinder in the broadest meaning of theword, can be circular, elliptical, or any other closed loop which may besuitable to the particular use of the stent 330.

The first portion 331 is structurally connected to the second portion332 and the third portion 334 by means of at least two bridges 333.Similarly to what has been described above, the bridges 333 engage alongthe closed loops defined by the cross section of the stent a firstlength p shorter than the second length S which is complementary to thefirst one and is not interested by the presence of the bridges 313 (thelengths P and S are not represented in FIG. 13 a for clarity reasons).In other words, the structural connection between the portions 331 and332 and the portions 331 and 334 of the stent 330 comprises a pluralityof bridges 333 unevenly distributed along the closed loop being definedby the cross section of the portions.

In accordance with an embodiment, the first length P is shorter thanhalf, preferably shorter than one third, and still more preferablyshorter than one fourth of second length S.

Furthermore, in accordance with a preferred embodiment, the y-y axis ofthe first portion 331, the z-z axis of the second portion 332 and thew-w axis of the third portion 334 are different. Furthermore, the closedloops being defined by the cross sections of the first portion 331 andthird portion 334 are at least partially comprised in the closed loopbeing defined by the cross section of second portion 332. Likewise, theclosed loops being defined by the cross sections of the first portion331 and third portion 334 are disjoint and have only a part of theirperimeter in common. In other words, the proximal end of the firstportion 331 is connected to the distal end of the second portion 332,and the proximal end of the third portion 334 by means of the bridges333.

In accordance with an embodiment, the bridges 313 have different lengthsand/or elasticities. In fact, those bridges that are closest to thecenter of the first length P of the closed loop are required to beshorter and/or less elastic than the bridges being arranged proximal ofthe ends of the first length P.

With reference to FIG. 6, with 400 there is indicated an assembly forthe treatment of stenosis according to the invention. The assembly 400comprises a first catheter 100 and a stent 310, 320 or 330 in accordancewith what has been described above. The assembly further comprises amandrel 180, preferably hollow, which is placed beside catheter 100. Theballoon 130 of catheter 100 is in its collapsed condition, being foldedabout the tubular body 110 of catheter 100. The first portion of thestent 311, 321 or 331 is fitted on the balloon 130. On the other hand,the second portion 312 or 332 is simultaneously fitted on the balloon130 and the mandrel 180. The second portion 322 or the third portion 334are fitted only on the mandrel 180.

In accordance with a preferred embodiment, the mandrel 180 of assembly400 also passes through the eyelet 150.

With reference to FIG. 7 with 500 there is indicated an assembly for thetreatment of stenosis according to the invention. The assembly 500comprises a first catheter 100 and a stent 310, 320 or 330 in accordancewith what has been described above. The assembly further comprises asecond catheter 200 being placed beside first catheter 100. Bothballoons 130 and 230 of both catheters 100 and 200 are in theircollapsed condition, being folded about the tubular bodies 110 and 210of the catheters. The first portion of the stent 311, 321 or 331 isfitted on the balloon 130 of first catheter 100. On the other hand, thesecond portion 312 or 332 is simultaneously fitted on the balloon 130 offirst catheter 100 and the balloon 230 of second catheter 200. Thesecond portion 322 or the third portion 334 are instead fitted only onthe balloon 230 of second catheter 200.

The second catheter 200 of assembly 500 also passes through the eyelet150 of first catheter.

The method for preparing the assembly 500 generally provides that,starting from the assembly 400, the mandrel 180 is removed from thestent 310 or 320 or 330 and from the eyelet 150, if required. The secondstent portion 312 or 322 or 332, and the third stent portion 334, ifprovided, form a slot which is partially engaged by the balloon 130 ofthe first catheter 100 and partially free.

After the mandrel 180 has been removed, the second catheter 200 has tobe selected based on the particular conditions of use. The distal end220 of second catheter 200 is then inserted in the eyelet 150 andadvanced until reaching the partially free slot being formed by thestent 310 or 320 or 330.

The distal end 220 is then inserted in the slot being formed by thestent 310 or 320 or 330. The second catheter 200 is then advanced overthe first catheter 200 until the shoulder 250 abuts against the eyelet150. Because the shoulder outer diameter and the eyelet inner diameterare such that the shoulder abuts against the eyelet without being ableto pass therethrough, an end of stroke is thereby formed univocallydefining a mutual positioning of both catheters 100 and 200, andparticularly of both balloons 130 and 230.

In accordance with an embodiment, the method described above providesthat the mandrel 180 be hollow. According to this embodiment of themethod, before removing the mandrel 180 from the stent 310 or 320 or 330and from the eyelet 150, if necessary, a stylet or guide wire 185 isinserted in the mandrel 180 and the eyelet 150. Thereby, after themandrel has been removed and the second catheter 200 has been fitted onthe stylet or guide wire 185, inserting the second catheter 200 in theeyelet and slot being formed by the stent is easier.

In accordance with an embodiment, upon completion of this insertion, thestylet or guide wire 185 is removed thus obtaining the assembly 500described above.

The method for using the assembly 500 according to the inventionprovides that the operator inserts, in a manner known per se, a coupleof guide wires along the patient's vessels such as to reach thebifurcation as desired. A first guide wire is placed within the sidebranch of the bifurcation, whereas the second guide wire is placedwithin the main branch.

After the catheters and the stent have been selected according to theparticular requirements and after the assembly 500 has been preparedaccording to what has been stated above, the operator inserts the firstcatheter 100 on the first guide wire and the second catheter 200 on thesecond guide wire.

The particular case of the first embodiment 310 of the stent will beconsidered below, but the description of this method likewise applies tothe subsequent embodiments 320 and 330 of the stent according to theinvention.

The catheters, by being advanced by the operator over the guide wires,almost automatically reach the position shown in FIG. 8. Due to theinteraction between the shoulder 250 of second catheter 200 and theeyelet 150 of first catheter 100, the relative position of both balloonsis univocally defined and maintained under the effect of the thrustapplied by the operator. In FIG. 8 there is illustrated a position wherethe proximal ends of the balloons are substantially aligned, but with adifferent arrangement of the eyelet 150 and shoulder 250 along therespective catheters, it is possible to determine other positions thatmay be particularly useful in several specific situations.

In accordance with an embodiment of the assembly, for example, theproximal end of the balloon 230 of second catheter 200 is arranged at acertain distance in the proximal direction relative to the proximal endof the first balloon 130, such that the proximal end of the firstballoon 130 is distally placed relative to the proximal end of thesecond balloon 230, as in the example from FIG. 4.

With this particular arrangement of both balloons being slightly offsetin the axial direction, an improved inner profile can be provided to thestent and accordingly to the bifurcation treated by the angioplasty.

After the assembly 500 has been moved to the position illustrated inFIG. 8, the operator brings the balloons from the collapsed condition tothe expanded condition.

In accordance with an embodiment of the method the inflation of bothballoons 130 and 230 is carried out at the same time.

In accordance with another embodiment of the method, the first balloon130 is inflated prior to second balloon 230.

In a manner known per se, the first balloon 130 dilates the stenosis andrestores the vessel inner diameter, which is thereby brought back tonon-pathological values.

By inflating the first balloon 130 the first portion 311 of stent 310 isalso dilated and brought from its collapsed condition to its expandedcondition. In the expanded condition, the first section 311 supports theinner walls of the side branch to avoid that, after the angioplastyoperation, they may shrink and reduce the inner diameter back topathological levels.

By inflating the balloons 130 and 230, the second portion 312 of thestent 310 is also dilated and is brought to its collapsed condition toits expanded condition. In the expanded condition the second section 312supports the area immediately proximal of the side branch, indicatedwith A in FIG. 1 a. As can be clearly seen in FIG. 10, after bothcatheters 100 and 200 have been removed, the stent 310 once definitelyplaced, is totally adhered to the bifurcation walls and does notinterferes at all with the blood stream. For this reason, if thebifurcation is affected by stenosis even along the main branch, thestent 310 according to the invention can be used by being coupled with astent b of the known type 600 being dedicated to the main branch of abifurcation. A situation of this type is shown in FIG. 15.

As refers to the specific characteristics of the second embodiment 320of the stent, it is particularly suitable for the treatment of thecarina area, which is indicated with B in FIG. 1 b. Due to the presenceof both cavi guida and the particular structure of the assembly 500according to the invention, the operator can place the stent 320 in theproper position in an almost automatical manner. In fact, the firstcatheter 100, following its guide wire, reaches the side branch and thusthe first portion 321 of the stent 320. The second catheter 200,following its guide wire, reaches the main length and the second portion322 of the stent 320. Under the thrust action by the operator, thebridges 323 connecting both portions of the stent abut against the cuspof the carina (see for example FIG. 12) thus univocally defining theposition of the stent in the bifurcation.

As refers to the specific characteristics of the third embodiment 330 ofthe stent, it is particularly suitable for treating both the moreproximal area of the bifurcation, being indicated with A in FIG. 1 a,and the area of the carina, being indicated with B in FIG. 1 b. In fact,the third embodiment comprises the characteristics of the first andsecond embodiments described above.

In accordance with an embodiment of the method for preparing theassembly 500, the operator inserts a first guide wire along thepatient's blood vessels until it is arranged in the side branch of thebifurcation in question. The guide wire 85 described above and insertedin the hollow mandrel 180 acts as the second guide wire, being arrangedin the main branch of the bifurcation. After the mandrel 180 has beenremoved, the first catheter 100 is advanced over the first guide wireuntil reaching the bifurcation. Only at this time the second catheter200 is fitted on the second guide wire 185 and advanced thereonto untilreaching the bifurcation. The second catheter will be automaticallyinserted in the eyelet 150 and the slot formed by the stent, such as toform the assembly 500.

The embodiments of the method described above for preparing the assembly500 do not substantially differ from the latter. The only difference isthat with this latter embodiment of the method, the second catheter 200will reach its operative position, i.e. with the shoulder 250 abuttingagainst the eyelet 150, when it is already inserted in the patient'sbody. Thus, this embodiment of the method is advantageous in that thecatheters run through the patient's vessels separately, the bifurcationinterested by the operation being thereby easier to reach. On the otherhand, the embodiments of the method described above are advantageous inthat they can be carried out at a separate time than angioplastyoperation. For example, the preparation of the assembly 500 from theassembly 400 and second catheter 200 can take place, once the size ofthe main branch and side branch of bifurcation are acknowledged, in alaboratory remote from the operation site.

To the above embodiments of the stent, catheters, assemblies and methodsthereof, those skilled in the art, aiming at satisfying contingentrequirements, may be able to carry out modifications, adaptations andreplacements of elements with others being functionally equivalent,without departing from the scope of the claims below. Each of thecharacteristics being described as belonging to a possible embodimentcan be carried out independently of the other embodiment described.

1. An endoluminal stent comprising: at least one first cylindricalportion having an axis and an annular section, said annular sectioncomprising a first length and a second length, and at least one secondcylindrical portion having an axis and being connected to said firstcylindrical portion, wherein the connection between said first andsecond cylindrical portions comprises at least two bridges and engagessaid first length of said annular section of said first cylindricalportion, said first length being shorter than said second length, andwherein said axis of said first cylindrical portion and said axis ofsaid second cylindrical portion are different.
 2. The stent according toclaim 1 comprising: a third cylindrical portion having an axis and beingconnected to said first cylindrical portion, wherein the connectionbetween said first and third cylindrical portions comprises at least twobridges and engages said first length of said annular section of saidfirst cylindrical portion, said first length being shorter than saidsecond length, and wherein said axis of said first cylindrical portionand said axis of said third cylindrical portion are different.
 3. Thestent according to claim 2, wherein said axis of said second cylindricalportion and said axis of said third cylindrical portion are different.4. The stent according to claim 1 wherein said connection is unevenlyarranged along the annular section of said first cylindrical portion. 5.The stent according to claim 1 wherein said first length is shorter thanhalf said second length.
 6. The stent according to claim 1 wherein saidfirst length is shorter than one third of said second length.
 7. Thestent according to claim 1 wherein said first length is shorter than onefourth of said second length.
 8. The stent according to claim 1 whereinsaid bridges have different lengths.
 9. The stent according to claim 1wherein said bridges are made of different materials.
 10. The stentaccording to claim 1 wherein said bridges have different elasticities.11. A catheter for endoluminal operations comprising a main tubular bodyhaving a distal end, a proximal end and a proximal port for a guidewire, said distal end comprising a balloon and a distal port for a guidewire, wherein an eyelet is placed at a preset distance in the proximaldirection relative to said balloon.
 12. The catheter according to claim11 wherein said eyelet is placed laterally relative to said tubularbody.
 13. The catheter according to claim 11 wherein said eyelet isintegral with said tubular body.
 14. The catheter according to claim 11wherein said eyelet defines an x-x axis being locally parallel to saidtubular body.
 15. The catheter according to claim 11 wherein said eyeletcomprises a slot of substantially unextensible thread.
 16. The catheteraccording to claim 11 wherein said eyelet comprises a tube length beingsubstantially fastened to said tubular body.
 17. The catheter accordingto claim 16 wherein said tube length is fastened to said tubular body bywelding.
 18. The catheter according to claim 16 wherein said tube lengthis fastened to said tubular body by means of gluing.
 19. The catheteraccording to claim 16 wherein said length of tube and said tubular bodyare made as one piece by extrusion.
 20. The catheter according to claim11 comprising a sheath simultaneously enveloping the tubular body andthe eyelet.
 21. The catheter according to claim 16 wherein said tubelength is cut along a plane perpendicular to the x-x axis.
 22. Thecatheter according to claim 16 wherein said tube length is cut along acurved and biased surface relative to x-x axis.
 23. The catheteraccording to claim 11 wherein said proximal port for the guide wire isproximally located relative to said eyelet.
 24. A catheter forendoluminal interventions comprising a main tubular body having a distalend, a proximal end and a proximal port for a guide wire, said distalend comprising a distal port for a guide wire and a balloon suitable tobe inflated, wherein a shoulder is placed at a preset distance in theproximal direction relative to said distal end.
 25. The catheteraccording to claim 24 wherein said distal end, when said balloon is notinflated, is suitable to be inserted in the eyelet of a cathetercomprising a main tubular body having a distal end, a proximal end and aproximal port for a guide wire, said distal end comprising a balloon anda distal port for a guide wire, wherein an eyelet is placed at a presetdistance in the proximal direction relative to said balloon, whereinsaid shoulder is not suitable to be inserted in the eyelet of saidcatheter.
 26. The catheter according to claim 24 wherein said shouldercomprises a step perpendicular to the outer surface of said tubularbody.
 27. The catheter according to claim 24 wherein said shouldercomprises a tapering joining the shoulder maximum diameter to thediameter of said tubular body.
 28. An assembly comprising a firstcatheter according to claim 11, a mandrel and a stent comprising atleast one first cylindrical portion having an axis and an annularsection, said annular section comprising a first length and a secondlength, and at least one second cylindrical portion having an axis andbeing connected to said first cylindrical portion, wherein theconnection between said first and second cylindrical portions comprisesat least two bridges and engages said first length of said annularsection of said first cylindrical portion, said first length beingshorter than said second length, and wherein said axis of said firstcylindrical portion and said axis of said second cylindrical portion aredifferent.
 29. The assembly according to claim 28 wherein said first andsecond stent portions are fitted on said first catheter and wherein saidsecond portion of said stent is fitted on said mandrel.
 30. The assemblyaccording to claim 28 wherein said first portion of said stent is fittedon said first catheter and wherein said second portion of said stent isfitted on said mandrel.
 31. The assembly according to claim 28 whereinsaid first and second stent portions are fitted on said first catheterand wherein said second and third portions of said stent are fitted onsaid mandrel.
 32. An assembly comprising a first catheter according toclaim 11, a second catheter comprising a main tubular body having adistal end, a proximal end and a proximal port for a guide wire, saiddistal end comprising a distal port for a guide wire and a balloonsuitable to be inflated, wherein a shoulder is placed at a presetdistance in the proximal direction relative to said distal end and astent comprising at least one first cylindrical portion having an axisand an annular section, said annular section comprising a first lengthand a second length, and at least one second cylindrical portion havingan axis and being connected to said first cylindrical portion, whereinthe connection between said first and second cylindrical portionscomprises at least two bridges and engages said first length of saidannular section of said first cylindrical portion, said first lengthbeing shorter than said second length, and wherein said axis of saidfirst cylindrical portion and said axis of said second cylindricalportion are different.
 33. The assembly according to claim 32 whereinsaid first and said second stent portions are fitted on said firstcatheter and wherein said second portion of said stent is fitted on saidsecond catheter.
 34. The assembly according to claim 32 wherein saidfirst portion of said stent is fitted on said first catheter and whereinsaid second portion of said stent is fitted on said second catheter. 35.The assembly according to claim 32 wherein said first and said secondportions of said stent are fitted on said first catheter and whereinsaid second and said third portions of said stent are fitted on saidsecond catheter.
 36. A method for preparing an assembly of a stent, afirst catheter and a second catheter, said method comprising steps of:arranging an assembly according to claim 28; arranging said secondcatheter; removing said mandrel such that at least a portion of saidstent is left free; inserting the distal end of said second catheter insaid eyelet of said first catheter; inserting the distal end of saidsecond catheter in said at least one partially free portion of saidstent; advancing said second catheter in the distal direction along saidfirst catheter until said shoulder comes in contact with said eyelet.37. The method according to claim 36, wherein before removing saidmandrel, a stylet or guide wire is inserted in said mandrel and saideyelet and the distal end of said second catheter is fitted on saidstylet or guide wire.
 38. A method for using an assembly according toclaim 32 in a bifurcation of a blood vessel being affected by stenosiswherein said method is characterized by the following steps: arranging afirst guide wire in a side branch of a bifurcation; arranging a secondguide wire in a main branch of a bifurcation; fitting said firstcatheter on said first guide wire; fitting said second catheter on saidsecond guide wire; advancing both catheters simultaneously along bothguide wires until said balloons reach said bifurcation; inflating saidballoons; deflating said balloons; removing said second catheter;removing said first catheter.
 39. The method according to claim 38wherein said balloons are inflated at the same time.
 40. The methodaccording to claim 38 wherein said first balloon is inflated before saidsecond balloon.
 41. A method for employing an assembly according toclaim 37 in a bifurcation of a blood vessel being affected by stenosiswherein said method is characterized by the following steps: arranging afirst guide wire in a side branch of a bifurcation; arranging said guidewire in a main branch of a bifurcation; fitting said first catheter onsaid first guide wire; fitting said second catheter on said guide wire;advancing said first catheter over said first guide wire until saidballoon reaches said side branch of said bifurcation; advancing saidsecond catheter along said guide wire until said shoulder comes inabutment against said eyelet; inflating said first balloon; deflatingsaid second balloon; deflating said balloons; removing said secondcatheter; removing said first catheter.
 42. The method according toclaim 41 wherein said balloons are inflated at the same time.
 43. Themethod according to claim 41 wherein said first balloon is inflatedbefore said second balloon.
 44. The method for employing an assemblyaccording to claim 37 in a bifurcation of a blood vessel affected bystenosis wherein said method is characterized by the following steps:arranging a first guide wire in a side branch of a bifurcation;arranging said guide wire in a main branch of a bifurcation; fittingsaid first catheter on said first guide wire; fitting said secondcatheter on said guide wire; advancing said first catheter along saidfirst guide wire until said balloon reaches said side branch of saidbifurcation; inflating said first balloon; deflating said first balloon;advancing said second catheter along said guide wire until said shouldercomes to abutment against said eyelet; inflating said second balloon;deflating said second balloon; removing said second catheter; removingsaid first catheter.